/***
 * ASM: a very small and fast Java bytecode manipulation framework Copyright (c) 2000-2011 INRIA,
 * France Telecom All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification, are permitted
 * provided that the following conditions are met: 1. Redistributions of source code must retain the
 * above copyright notice, this list of conditions and the following disclaimer. 2. Redistributions
 * in binary form must reproduce the above copyright notice, this list of conditions and the
 * following disclaimer in the documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the copyright holders nor the names of its contributors may be used to
 * endorse or promote products derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY
 * WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package com.googlecode.aviator.asm.commons;

import com.googlecode.aviator.asm.Handle;
import com.googlecode.aviator.asm.Label;
import com.googlecode.aviator.asm.MethodVisitor;
import com.googlecode.aviator.asm.Opcodes;

/**
 * A {@link MethodVisitor} that can be used to approximate method size.
 *
 * @author Eugene Kuleshov
 */
public class CodeSizeEvaluator extends MethodVisitor implements Opcodes {

  private int minSize;

  private int maxSize;

  public CodeSizeEvaluator(final MethodVisitor mv) {
    this(Opcodes.ASM4, mv);
  }

  protected CodeSizeEvaluator(final int api, final MethodVisitor mv) {
    super(api, mv);
  }

  public int getMinSize() {
    return this.minSize;
  }

  public int getMaxSize() {
    return this.maxSize;
  }

  @Override
  public void visitInsn(final int opcode) {
    minSize += 1;
    maxSize += 1;
    if (mv != null) {
      mv.visitInsn(opcode);
    }
  }

  @Override
  public void visitIntInsn(final int opcode, final int operand) {
    if (opcode == SIPUSH) {
      minSize += 3;
      maxSize += 3;
    } else {
      minSize += 2;
      maxSize += 2;
    }
    if (mv != null) {
      mv.visitIntInsn(opcode, operand);
    }
  }

  @Override
  public void visitVarInsn(final int opcode, final int var) {
    if (var < 4 && opcode != RET) {
      minSize += 1;
      maxSize += 1;
    } else if (var >= 256) {
      minSize += 4;
      maxSize += 4;
    } else {
      minSize += 2;
      maxSize += 2;
    }
    if (mv != null) {
      mv.visitVarInsn(opcode, var);
    }
  }

  @Override
  public void visitTypeInsn(final int opcode, final String type) {
    minSize += 3;
    maxSize += 3;
    if (mv != null) {
      mv.visitTypeInsn(opcode, type);
    }
  }

  @Override
  public void visitFieldInsn(final int opcode, final String owner, final String name,
      final String desc) {
    minSize += 3;
    maxSize += 3;
    if (mv != null) {
      mv.visitFieldInsn(opcode, owner, name, desc);
    }
  }

  @Override
  public void visitMethodInsn(final int opcode, final String owner, final String name,
      final String desc) {
    if (opcode == INVOKEINTERFACE) {
      minSize += 5;
      maxSize += 5;
    } else {
      minSize += 3;
      maxSize += 3;
    }
    if (mv != null) {
      mv.visitMethodInsn(opcode, owner, name, desc);
    }
  }

  @Override
  public void visitInvokeDynamicInsn(String name, String desc, Handle bsm, Object... bsmArgs) {
    minSize += 5;
    maxSize += 5;
    if (mv != null) {
      mv.visitInvokeDynamicInsn(name, desc, bsm, bsmArgs);
    }
  }

  @Override
  public void visitJumpInsn(final int opcode, final Label label) {
    minSize += 3;
    if (opcode == GOTO || opcode == JSR) {
      maxSize += 5;
    } else {
      maxSize += 8;
    }
    if (mv != null) {
      mv.visitJumpInsn(opcode, label);
    }
  }

  @Override
  public void visitLdcInsn(final Object cst) {
    if (cst instanceof Long || cst instanceof Double) {
      minSize += 3;
      maxSize += 3;
    } else {
      minSize += 2;
      maxSize += 3;
    }
    if (mv != null) {
      mv.visitLdcInsn(cst);
    }
  }

  @Override
  public void visitIincInsn(final int var, final int increment) {
    if (var > 255 || increment > 127 || increment < -128) {
      minSize += 6;
      maxSize += 6;
    } else {
      minSize += 3;
      maxSize += 3;
    }
    if (mv != null) {
      mv.visitIincInsn(var, increment);
    }
  }

  @Override
  public void visitTableSwitchInsn(final int min, final int max, final Label dflt,
      final Label... labels) {
    minSize += 13 + labels.length * 4;
    maxSize += 16 + labels.length * 4;
    if (mv != null) {
      mv.visitTableSwitchInsn(min, max, dflt, labels);
    }
  }

  @Override
  public void visitLookupSwitchInsn(final Label dflt, final int[] keys, final Label[] labels) {
    minSize += 9 + keys.length * 8;
    maxSize += 12 + keys.length * 8;
    if (mv != null) {
      mv.visitLookupSwitchInsn(dflt, keys, labels);
    }
  }

  @Override
  public void visitMultiANewArrayInsn(final String desc, final int dims) {
    minSize += 4;
    maxSize += 4;
    if (mv != null) {
      mv.visitMultiANewArrayInsn(desc, dims);
    }
  }
}
